


Not So Innocent

by Skelespoo



Category: Undertale (Video Game)
Genre: Consensual Sex, Dirty Talk, EctoTongues, Ectovagina, Fontcest, M/M, Masturbation, NSFW, Praise, Sibling Incest, Swapcest - Freeform, Swearing, Voyeurism, ectodick
Language: English
Status: Completed
Published: 2016-12-05
Updated: 2016-12-05
Packaged: 2018-09-06 17:47:40
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 7,620
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8762854
Author URL: https://archiveofourown.org/users/Skelespoo/pseuds/Skelespoo
Summary: Papyrus decides to peep in on his older brother taking a shower but little did he realize how true his desires were going to unfold that day.





	1. Part 1

God I’m such a freak.

 

It was a familiar mantra that always played in the taller skeleton’s skull, one that was aided by conflicting emotions most of which was shame. Here he was living in the Underground and was well known to be the most laziest sack of bones there was, yet the only thing that mattered to him that even remotely made him consider getting out of bed in the first place was his brother, Sans. Or rather Blue as he was often called by the vibrant blue bandana around his neck. Yes his brother was the most important thing to him but this was where things got complicated. He loved him..a lot more then what a normal brother should be. He didn’t know how or when it started but over time that infectious smile as well as his positive attitude just seemed to make Papyrus’s soul melt. However because of that he now had to deal with not only keeping it a secret, but to make sure he kept himself in line which by all means Sans certainly wasn’t making it easy for him. They did live in the same house after all.

 

He had been laying on his bed lost in thought earlier when he heard his brother call from outside his room, saying he was going to take a shower after having trained that day with Alphys, the younger sibling muttering a curse as the bathroom was pretty much right next to his room and in no time he could hear water coming from the nozzle head. Papyrus had tried, oh how he had tried to contain the lust filled hormones stirring up lewd images, trying oh so hard not to picture his sweet innocent older sibling utterly naked with water flowing down his petite body like an elegant waterfall. Sadly It was all in vain however, a minute or two passing before he quickly shuffled out of bed going to the farthest wall where a silly poster hung. Actually why would he need to picture it when the answer was right there in front of him?

 

Peeling back the tape the picture fell to the floor, revealing a small hole no bigger then enough for his black pupil to see through, a thing he’d made for himself for just such an occasion and now it was going to be put into use. He had to sit on his hunches in order to get a good view on account of San’s height but that didn’t matter once he leaned in close, a shuddering sigh of longing escaping his mouth. He could see the shorter monster washing himself up without a care, lathering up some soap to wash away the dirt and smell..god it was a beautiful sight to behold. “..F-Fuck..” Papyrus muttered while his magic stirred within him, an orange ecto like tongue licking over his teeth; his hand beginning to kneed himself between his legs.

 

“ _God..I’m such a freak..but I can’t help it..you don’t know how badly I want you”_ he thought to himself as he held back a whimper even though probability of Sans hearing him was slim on account of the rush of the shower. Still that only added more excitement on his part, getting that rush of adrenaline knowing he was just on the other side of the wall jerking his boner, no pun intended, thinking of all the things he wished he could do to his adorable sibling. It was sick, twisted even and yet..he couldn’t deny that he loved it. Unable to take it his phalanges frantically tugging the zipper of his fly, his other hand covering his mouth once his cock was free from its confinements; throbbing and already weeping for attention.

 

“Ngh..haa fuck..yes..S-Sans..” he grunted as a shiver ran up his spine once his hand began pumping his cock, still trying to keep an eye through the peephole. Watching his brother continue to wash and even turning at a certain angle made his soul skip a beat, the taller monster’s imagination running free as Papyrus tried to picture what it would be like to have his mouth wrapped around his dick. Of course fantasy wouldn’t compare to the real thing but it did its job well. A wisp of orange light surrounded his right eye socket, tongue poking out of his mouth as his breath came out in low pants while the image played in his mind. 

 

Envisioning the smaller skeleton down on his hands and knees with his cute round mouth opening up just to tease him by suckling his tip made Papyrus’s growl lustfully, “Ghngh y-yeah just..like that..take it all into that mouth of y-yours..mmn like a g-good boy..”. As the fantasy got more intense so did his movements as his hand moved faster and rougher causing his hips to slightly thrust into the amazing friction, head tossing back, “Haa..ahn..ugh god damn it Sans..I..I want to fuck you so bad..I-I..nnm..want to show you..h-how good I’d make..you f-feel mmngh!”. It was funny how much he loved his brother’s innocence and yet part of him wanted so badly to be the first to corrupt him; to take something nobody else would get.

 

Man this was torture, feeling so hot and yet he couldn’t stop himself now. Not when he was almost reaching that delicious peak of orgasm and as the imaginary Sans sucked his dick like an eager slut did Papyrus rest one of his arms on the wall, his skull pressed against it as beads of sweat formed against his brow; eyes having closed shut allowing himself to be thrown into the sea of pleasure as he continued stroking his slick appendage. He would have kept going had the self conscious part of himself suddenly, if only for a moment, begin to notice that it was strangely quiet in the bathroom. That thought alone was to make him suddenly stop all movements, his eye sockets snapping open upon sucking in a breath quickly; moving his head to peep through the hole.

 

The other side was empty, the water now silent and no sign of his sibling anywhere.

 

 _“Uh oh..shit where..how long was I..?”_ Papyrus thought however the sound of someone clearing their throat made a cold shiver run down his frame in realization, feeling his sins crawling upon him as his head slowly turned to look towards the front of his room. There standing in nothing but a towel dripping wet still was Sans, arms crossed and boy did he not look very impressed.

 

Busted..


	2. Part 2

It felt like several long agonizing minutes passed as Papyrus sat rooted on the spot, his dick still aching between his legs and for a moment he almost completely forgot about it since it was all coming down upon him that this was seriously happening. That he’d foolishly been caught red handed in the act..what was he supposed to do? Joke it off? That would be kind of hard to do in this type of situation so all he could really think to do was lower his head with guilt and shame written all across his face, a light orange hue gracing across his cheeks while his hands did their best to cover himself up from the glowering eyes radiating of his brother. God the tension was so thick one could cut it with a knife yet he couldn’t allow himself to speak, the words just not forming properly for him to break the silence. That was until Sans was the one to speak up.

 

“So..” the smaller monster spoke in a taunt manner, his expression still slightly displeased as his arms crossed in front of him in order to hold the damp towel closer around his form, which made the younger sibling do his best not to dare look at him try as he might for fear of his arousal twitching behind his hands, “This is what you’ve been doing? ..I’m honestly not surprised. I could have sworn that spot on the wall in there looked suspicious but never gave it much thought..until now”.

 

Papyrus didn’t like this at all. He was expecting to be blown up at whenever he’d made a lewd comment or gesture in the past so it felt so eerie to him that this wasn’t happening right off the bat, a ton of thoughts and fears screaming in his skull. Shit..he fucked up. Sans hated him now. He probably thought he was some big ass pervert..which he was..but granted he would never allow himself to take advantage of his sibling without his consent. He would rather turn to dust then allow that to happen and that was why a lot of times he went to Muffets to drink so heavy he’d pass out, hoping to tame his sexual hunger when days got too bad to handle it when sober. Of course now that wouldn’t matter, because at this rate his brother was probably going to kick him out. Or worse. Never want to see him again..oh no how could he ever handle that?

 

“Papyrus..look at me..”.

 

The taller skeleton shook his head as he was brought back into reality from his thoughts, his jaw tightening as he could feel the liquid of tears forming in his eye sockets to which he covered his face with the sleeve of his honey stained hoodie, refusing to look in his direction. “N-No I..I’m sorry, bro..I can’t..I’m sorry..I’m sorry! I didn’t..p-please don’t hate me”. There was silence at first as Sans didn’t respond but even though Papyrus couldn’t see it he could hear something hit the floor followed by small footsteps heading in his direction; his body visibly tensing as he could sense the presence of his brother close to him. Fuck what was he going to do now? 

 

“Papy..look at me..” Sans requested once more though his voice was much more soft and coxing this time, the tone allowing the young monster to slowly relent into the tempting voice as he timidly unhid his face curious now as to why the other still hadn’t chewed him out like he should be. The sight before him took his breathe away, feeling his soul jump into his ribs as his older brother was sitting on his knees in front of him naked as the day he was born, the towel having been discarded. Those baby blue orbs were gazing at him with a mixture of emotions, namely concern and fondness from what Papyrus could gather but before he could turn his head away did he feel Sans’s smaller phalanges were placed on either side of his skull, gently forcing him to continue facing him.

 

“Hey..hey come on now, don’t cry..I don’t hate you”.

 

“W..Wha..but..why? I don’t understand”.

 

Well now this was not how he was thinking things were supposed to go. He was expecting anger and disgust not comfort, blinking in surprise as his brother’s fingers tenderly wiped at the corner of his eye sockets before any tears had a chance to fall. Once Sans pulled back did he let out a sigh as a darker blueish hue started to grace his round angelic face for he couldn’t help but notice Papyrus trying to still hide himself despite it not really working too well before his gaze returned back to his sibling. “I admit..I am a little mad, but that’s more because of finding out that you were spying on me” he replied with a clear of his throat almost shyly looking off to the side as he rubbed the back of his skull, “I’m still not really sure how I should feel about..seeing you do such..things..”.

 

“Y-You were watching me masturbate?”.

 

Sans’s face burned brightly at the question and his eyes snapped back towards the other skeleton, puffing his cheeks out childishly as he yelled, “N-NO! I..I wasn’t..I j-just heard moans and..and..s-shut up, Papyrus”. Seeing something familiar to him made Papyrus unable to help himself into beginning to chuckle from witnessing the adorable reaction, only further making the other frown slightly annoyed that he was being teased but at least the atmosphere felt a little bit better between them. Still..the elephant in the room hadn’t quite left and sooner or later both of them would have to acknowledge the fact that the young monster was still rock hard and dimly glowing from behind his silly form of protection, Sans’s gaze once more look downward and beginning to fidget awkwardly.

 

“A-Anyway..I..I don’t hate you, Papy. I could never hate you..you’re my brother” the older sibling spoke softly before pausing a moment as if he seemed to be considering something yet unsure of it, “And..even though I didn’t know or knew how long you felt for me..like that..even though I know its wrong..I..I want to help you”. Those last few words briefly didn’t register in the slacker’s mind, at first just staring at his sibling like he’d grown two heads only when it did manage to click did his face begin to blush darkly, giving his head a rapid shake.

 

“W-W-What!? S-Sans no! You don’t have to do that!”.

 

“Why not?”

 

“B..Because! I..it’s complicated alright? I don’t want you doing something your forced to do..”.

 

Sans rolled his eyes at what he considered a lame objection, his body leaning forward only for the other skeleton to move back, realizing that he was still sitting in the same position from earlier and promptly fall onto his rump which allowed his brother to have more room to shift in between his legs; his boney hands fumbling as he tried to hide his erection now with the hem of his hoodie pulled down over it. “You’re not forcing me to do anything” he replied matter of factly and before Papyrus could push him away or protest further did he feel his soul suddenly freeze as it turned blue, his back being pressed against the wall by some invisible force. 

 

Course the answer to that was it had been brother that was using his magic to hold him in place as evident by the paler blue light glowing around his left eye socket, shit when had he learned how to do that before? The taller skeleton didn’t have much time to think nor could he exactly struggle out of it as a shiver ran down his spinal cord, watching helplessly upon Sans pulling away his cover up, his cock springing free from the movement. This was weird. This wasn’t like his brother to be so.. _forward_ and he felt conflicted about it. Like it was a dream come true and yet so strange it just felt too out of place for this to be happening. Not to mention he couldn’t just blame it on being in heat because he’d know all too well if that ever happened. 

 

“Y-You don’t..S-Sans stop! Don’t do this, this isn’t like you..l-let’s just forget about this and let me handle it huh? W-We can even make tacos toget–haangh!” Papyrus tried to plea once more only for his words to drown out into a moan upon feeling his sibling’s hands begin to test the waters by beginning to touch his ectoformed cock, his hands so small they could almost barely close around his dick it was that thick and pent up from lack of attention.

 

“I’m not a child anymore Papyrus” Sans huffed lightly with a frown though it melted once he saw the bliss even though the other was trying to fight for control but not having much luck as he continued gaining more courage in stroking the warm throbbing arousal, “I’m well aware to some extent about..this kind of stuff. So just..let me help you ok? After all I did interrupt you having a good time, mweh heh”.

 

“B-But..mmn!..Y..You don’t..lo-aahn..love me..as much a-as I do..nn..y-you”.

 

“..True..but I’m willing to learn”.


	3. Part 3

Wait, what? What did Sans mean by that? As much as those words had caught the taller skeleton off guard it was quick to melt away as the pleasurable sensations overcame his sense of logic, shivers running all the way down through to his pelvis and straight down to his legs. He didn’t bother to fight it anymore as Sans continued pumping his cock, relenting some of his hold on his sibling enough to allow him to move if just a bit; his hips shamefully thrusting eager to feel more of those hands touch him. His tongue reappeared from his gaping mouth, licking across it while his eyes remained glued on the one true being that gave his life purpose. Dear lord he seriously hoped this wasn’t going to be a dream because if so he never wanted to wake up from this heaven.

 

“My, my..you really are liking this aren’t you?” Sans giggled softly as his hands kept stroking his brother, that hesitant feeling he felt earlier now completely gone the more comfortable he grew. That and he couldn’t deny it. As wrong as this was, of doing this to his own blood, it all flew out the window when he could see for himself just how much Papyrus was going crazy over him. To think that all this time when he’d heard his muffled cries in his room growing up, it wasn’t being pent up over some female monster like he thought. It was him, always him and nobody else. Such warmth he felt in his ribs was amazing and now all he wanted was to make him feel wonderful. It was actually rather cute seeing him so worked up and horny.

 

“F-Fuuuck yes..” Papyrus moaned out, a low whine escaping him in lust for his gaze never faltered away from his brother, his soul starting to glow under his hoodie and it made his mood soar when in return he could see the smaller monster’s own dimly through his chest; that blue flush across his cheeks  turning darker. A blue ecto tongue of the smaller skeleton’s own licked across his teeth, eyes looking up and down from his brother’s face to the warm heat that his boney fingers moved against nor did he stop as his pace turned faster which made Papyrus cry out in ecstasy. “ _What is..this feeling? It feels really warm in here all of a sudden..”_ Sans thought to himself briefly and as his stare became almost hypnotized by the weeping cock in front of him he didn’t realize just how strongly his own magic was stirring from the eroticness of the situation he was putting himself through.

 

Among the whines and curses emitting from the taller monster he could see it all from his front row seat, a growl coming forth as an aqua blue vagina was now forming between his sibling’s legs which only heightened his arousal further at the beautiful delicacy that called out to be touched. “Nnmmn..Nyeh..heh..gee bro I..haaghn..didn’t think y-you’d be e-enjoying it this much” he managed to chuckle out to which the other merely blinked as he had came out of the trance, looking down at himself upon now noticing just where the heat was coming from. 

 

He’d been so focused he hadn’t realized what was happening so when it dawned on him on what he was seeing down there he let out a sudden yelp in horror; his hands sending such a strong squeeze around Papyrus’s cock that the younger male arched his back upward at the pain. Fucking hell he almost came right then and there but luckily Sans had pulled his hands away before anything further could happen, the hold around his soul now gone once his sibling turned his back away now fully concerned about his own appearance.

 

Cradling his cock momentarily and letting out a shaky breath, despite not having any lungs, black pupils looked up towards his brother’s back and partially able to catch what he was rattling off once he regained some of his composer from the sudden grip. “Aaah! Oh stars I didn’t..! I-I..w-what is this? Paaapy! What is this?!” the shorter skeleton whined in confusion and fear, the confidence he had completely gone and was now pretty much showing a normal trait that the other always saw when it came to things he didn’t quite understand. But..wait hadn’t Sans said he had read up on this type of stuff before? Why was he freaking out over forming a vagina? Unless..had he been lying this whole time? 

 

As horny as Papyrus was did his protective brotherly nature overpower his need for release temporarily, his hands softly pulling his sibling from behind into his chest while his chin cradled in the crook of the other monster’s neck, unable to stop himself from containing a snort because even he was a little confused as well, “Shh..relax bro. It’s just a vagina, it’s what females have..I..er..thought you said you read up on this sort of thing?”.

 

“I-I-I did! B..But..w-well I..I never..really..you know..” replied Sans with a deep blush spreading further across his face while trying hard to ignore his brother’s cock pressing against his hip bone, looking away in utter embarrassment for his body forming a part he thought wasn’t fitting of him, “ And I’m a male! I should have what you got!”. Either he was admitting he hadn’t read so far into the material or that he hadn’t experimented touching himself before made Papyrus’s cheek bones flush brightly, his grip tightening his hold on his brother while nuzzling into his neck which earned him a pouting protest thinking he was being made fun of. Dear god how could he be even more cuter then he already was?!

 

“..You’re mocking me aren’t you?”.

 

“W..What? No! No, no it’s just..Nyeheh..you’re so cute, Sans” he chuckled back as he stopped his affectionate nuzzle but now his eyes wandered down the lithe form of the other, glazing over the perfect dimly glowing sexual organ, “Don’t get discouraged bro. A monster’s body forms whatever feels right, mostly when it comes to us skeletons. It doesn’t make you any less of a male..plus..”. His words paused briefly as a hand grew bold enough to roam down Sans ribs, past his spine and before his brother could ask what he was doing did a gasp escape from his round mouth that was like music to Papyrus; his digits beginning to play with the folds of the precious flower, “..I hear you can have a lot more fun with a pussy”.

 

A pleasant jolt shot up through the smaller male’s form, his phalanges digging into the soft material of the hoodie’s arm and as his brother’s larger fingers began softly stroking him while occasionally pinching his clit, unable to stop himself from letting sweet moans coming out, panting Papyrus’s name. “Haa..haan..P-Papy it f-feels..” he tried to stutter out but another tremble shook through his bones and one of his hands covered over his mouth, the sensation strange to him yet not unpleasant. The more the other continued teasing him the wetter he was getting. Not to mention it only made the pooling heat grow even more.

 

“Does it feel good?” the lanky skeleton smirked faintly to which as he pushed in a finger deeper and hearing the blissful cry only further answered his question, growling as his hips began grinding his still aching cock against his sibling’s lilac crest, finding himself going crazy and wanting to hear more of those delicious sounds coming out of his sibling’s mouth, “S-Shit..you’re so fucking adorable Sansy..nnm you’re so wet for me..Do you want to feel more?”. When he was answered by a nod as he felt still too embarrassed to say anything by such lewd words being whispered huskily against his neck did the younger sibling press on, his tongue licking once more across his mouth hungrily.

 

“Good. Cause now it’s _my_ turn”.


	4. Part 4

The messy room was filled with a mixture of soft pants and mewling groans of bliss as the brothers remained sitting on the floor with Papyrus holding the other against his chest, sitting partially at an angle between his legs, their bodies rocking into each other trying to feel more of that heavenly bliss that they were sharing. Wet squelching noises began playing in tune with their rhythm as the taller monster slipped in a second digit to join the first finger and didn’t waste time in scissoring them in and out of Sans’s wet pussy which made the smaller skeleton dig his phalanges tighter into his arm; tossing his head in a sharp moan.

 

“..F-Fuck..” Papyrus growled for his own hips kept grinding onto the outer lilac crest, orange glowing liquid of precum smearing against those perfect white bones.

 

God it was so warm, his soul felt like it was molten lava burning within his chest, his fingers wet as they continued probing the lovely see-through blue squishy like innards of his sibling’s vagina, his throbbing cock threatening to explode but yet it couldn’t because he knew this wasn’t enough. He needed more. A lot more. But..he could never force himself upon his darling Sans. Never in a million years, unless he asked for it of course. For now he was just settling on the fact that this was even happening at all, and he was surely going to milk every drop of this moment. Who knows what tomorrow would be like but the slacker wouldn’t think about that.

 

Instead he turned his gaze towards the other monster, who’s adorable face was flushed and his bones shivering from the onslaught of sensations, drool coming from his partially agape mouth letting out breathless moans among other incoherent words; baby blue eyes were unable to help but look down as he watched Papyrus’s digits continue bobbing in and out. This feeling, it felt wonderful to him and yet at the same time..instinct was telling him this wasn’t enough. That this was just barely scratching the itch and at first part of the shorter skeleton wasn’t sure what it was exactly he wanted.  

 

A gasp then resounded from his mouth upon his brother’s tongue starting to lick up the side of his neck leaving a trail of thin saliva in his wake, body arching upon hearing those lewd words breathe against his collar bone.

 

“M-Mnn..haa..hangh shit..Y..Y-You like that, bro? Does it.nn..f-feel good huh? Nyeheh..wow you’re r-really..gugnh..s-soaking me to the bone aren’t you?”.

 

“A-Ahn! Ahh! D..Don’t..s-say things..nnm..l-like that…Haa..haa..P..Pap..Papyrus! Papy p-please..More..give me more!”.

 

Papyrus’s brow arched unsure as to what exactly Sans was referring to but by damn he wasn’t going to say no to such a beautiful blushing mess in front of him, a wave of surprise hitting him when the others craned his skull to look at him and clacking their mouths together just as a third bony finger entered and his hand moved more faster then before; returning the kiss hungrily as his tongue quite easily slipped past and sloppily did their magic muscles intertwined and danced against each other. 

 

At first this seemed to be doing the trick for Sans was reacting like a cat in heat as his cries once pulling away from the kiss were louder and almost demanding; the smoker’s hand starting to hurt as he kept moving his fingers roughly in and out but he wouldn’t stop. Not until he got to see him reach his first orgasm which surprisingly his older brother was holding out a lot longer then he thought he would.

 

“Hhaa! Hnn..w..wait..S..Stop..Stop!”.

 

Like a statue did the taller skeleton cease all movements at the words, both of them using this opportunity to catch their breath but Papyrus didn’t dare press onward for that was his number one rule he’d follow no matter what. If his sibling told him to stop he would without question. Still he was a bit confused as to why Sans wanted him to stop which further showed upon his face as tenderly his sibling began uncoiling himself from his embrace, glowing juices covering his digits and running down one of his legs while shakily getting up to his feet. Shit..had..had he done something wrong? Why did he want them to stop? Was he not enjoying this? Millions of questions wracked through the younger brother’s skull, worried that he’d overstepped something but it didn’t seem like the other was mad.

 

He watched him wobble like a newborn foal towards the towel and for a split second he seriously almost considered the possibility that the light of his life was going to just leave him hanging there, but no. Instead Sans picked up the discarded towel only to lay it down on the dirty mattress, the springs squeaking softly upon his short body getting on top of it. What happened next made a low whine escape Papyrus’s throat, watching his darling Sans lay on his back on the partially damp fabric, his legs spreading wide in full view like a lotus in bloom with shy eyes beckoning him to come closer.

 

“..Papy..I-I..I want more..t-then your fingers..p-please..”

 

“E..Eh? Bro are you..are you really sure this is what you want? You do know what you’re..asking me to do..right?”.

 

That little nod in response was all it took to break Papyrus’s last restraint, moving probably the quickest he’d ever moved in his entire life as he crossed from the wall towards his bed in a flash; hands resting upon his brother’s knees licking his mouth hungrily. Holy shit this was seriously going to happen! All of his dreams were coming true at this exact moment and he would have shifted himself more onto the bed when he was brought out of his thoughts upon Sans raising a hand for him to stop before he went any further, once again finding himself freezing in place.

 

“Huh? What’s wrong, Sans?”.

 

“N-Nothing just..I want you to do something for me first..b-before we started”.

 

Now this was surprising. What could possibly be going through his brother’s mind? Course he didn’t need to exactly think twice on it as the other pointed towards his shirt, flushed gaze upon him, “Take off your hoodie”. As strange as that request was the young skeleton didn’t seem to think too much of it and decided being the good brother he was to oblige to Sans wishes, the sound of cloth ruffling as he pulled the oversized shirt up over his head to reveal a black thin tank top underneath which accentuated the broadness of his skeletal form.

 

“I had no idea you wanted to see with my shi-.W-Whoa!”.

 

He didn’t know exactly how it happened, everything shifted so fast upon feeling himself being tugged downward onto the bed, the mattress squeaking as their bodies shifted around a bit and until it all managed to click in was Papyrus finding himself now on his own back, his arms tied behind him with the sleeves of his honey stained hoodie; cheeks burning in surprise and lust at the sight of Sans now hovering over his throbbing meat. “There..you had your fun, now it’s my turn again, mewhehe” he chuckled as the confidence once again was now returning like before, not that the other monster minded at all, a low gasp coming from from his round mouth upon teasingly letting his blue wet flower begin to rub along the side of his brother’s cock feeling the pulsing heat against him to which Papyrus’s eyes rolled back at the sensation; series of shivers running down his body.

 

“Ngh! F-Fucking-! S-Saaans you c-cheeky devil!”.

 

Another giggle arouse from Sans mouth, continuing to tease his brother as his juices coated along his ectodick, the taller monster trying desperately to feel more but on account his hands being tied up didn’t have much to support himself. “S..Shit bro I can’t..god I want you so bad!” Papyrus begged for if this didn’t let up soon he’d blow his load and he wanted to hold out for as long as he possibly could otherwise this would all end too soon. And he wanted to make it last because who knows he might not ever get this chance again. Hearing his pleas did the shorter skeleton stop his movements if only to lean a bit forward as he softly placed a kiss upon the others mouth before leaning back upward, hungry black pupils watching him for the tip of his cock just hovered mere inches from that delectable pussy ready to devour him into a world of pleasure that not even hands could satisfy.

 

“Alright, alright I’ll stop..I love you, Papy”.

 

“Haa..ahn..I love you too Sans..uhm..h-hey go easy up there alright? Don’t force yourself”.

 

“I won't” replied Sans with a nod, cheeks burning brightly as he geared himself up for what was to come knowing fully well that once this happened there was no turning back and as he held onto his brother’s legs for support did he slowly lower himself down.


	5. Part 5 (final)

Their cries rang out in unison as the blue lips parted, the tip of the glowing orange cock being the first to enter inside as Sans slowly moved himself downward upon the throbbing rod. Like actual muscles the youngest monster could feel it tightening instinctively around him which made him want to buck his hips upward into the magical warmth that surrounded him yet he had to do whatever it took to hold himself back; not wanting to cause the other any further discomfort that he was clearly going through at the moment as evident by the mixture of a whimper surfaced. He wasn’t even half way in yet when he had to stop for a moment, Papyrus seeing his member partway through the barrier and ready to slip through the hole in his pelvis.

 

“N..nnm..A..Are you..s-sure it’s going to fit? It’s so..b-big..”.

 

“Nyeheh..i-it’ll fit, bro..don’t..mmn..worry you’re doing..j-just fine..take it slow” Papyrus whispered huskily in order to encourage the other more, his right eye glowing eagerly awaiting for the love of his life to move once more which luckily he didn’t have to as Sans nodded meekly; swallowing a non existent lump in his throat and with a wincing yelp did he feel his brother’s cock fully enter right down until he was almost sitting on top of his pubis, causing the younger monster to let out a moan in delight from the sudden movement. Being a skeleton didn’t mean they had the benefits of having flesh or squishy organs to cover much like how regular sex worked with humans, but the smoker wouldn’t change any of that for the sight that greeted his vision was absolutely perfect.

 

Witnessing his darling resting between his legs, a blue flush spread across his face that held a mixture of emotions at the moment while he adjusted to the strange new feeling, seeing the shivers tremble through his small bones while his cock was covered in a thin veil of Sans’s magic as if to stimulate that he was now ‘inside’ of him..dear god it was too much. Papyrus couldn’t help himself but to let out a growl hungrily for his sibling while briefly wiggling his shoulders, trying to escape free from his binds but somehow or another it seemed to be surprisingly done tight for a pair of hoodie sleeves.

 

Fuck he wanted to touch him so bad, to run his distal phalanges along his ribs and vertebrae, wanting to find every sensitive spot he could just to see the shorter monster go wild but..he’d have to patient for now. Hell he’d waited this long and already here they were sharing their first intimate moment together which was still hard to believe that it was happening still. He was pretty sure he could wait a bit longer..probably..maybe.

 

Meanwhile Sans had managed to get  himself comfortable a little bit once giving himself a minute or two, his confidence deflating slighty into shyness upon seeing the uttermost desirable look radiating from Papyrus who’s eyes never left over his form but certainly seemed to be doing all that he could to not push himself and make him feel uncomfortable. Nobody had ever shown such an emotion towards him before so while it might be new he certainly was flattered, not to mention was even more happy that it was coming from someone who the closest thing to him since they were born. It gave him all the more determination to continue through with this, even if the chances of things getting awkward later were high. He wanted this, they both did.

 

Adjusting himself by sitting up a bit more did he start to slowly raise himself upward, letting his sibling’s ectocock shift about halfway before slamming back down again upon it, yellow pupils turning into hearts at the sensations trembling through him. While it was still was a bit discomforting that soon quickly melted away the more his movements continued as he rode Papyrus; mewling moans and pants escaping him mixed with the taller skeleton’s own groans of lust.

 

“A-Am..am I..nngh..haaahn..d-doing good, P-Papyrus? L-Like..this?”.

 

“F-Fucking hell, yes! J-Just..like that..Haa..nghnmn..y-you’re doing..so good Sans..mmn..such a good boy”.

 

Hearing such loving praise even though normally he’d have a problem with Papyrus cussing all the time he ignored that bit; focusing on his sibling’s words and the building pleasure that made him feel like his body was on fire, the pace now turning into a steady solid rhythm now as he continued riding Papyrus’s cock. Their souls as if reacting like sonar waves pinging off of objects reacted to one another and were glowing through their rib cages faintly which only further pushed Sans to want to experience more of the blissful sensations and share this wonderful moment with his younger brother; his digits running along his sternum however upon feeling the other monster’s hips began to meet up with his movements did he let out a sharp gasp in delight.

 

“A-Ahn! Haa! P-Papyrus!” he cried out with his skull tossing back, tongue poking out past his teeth with drool dripping from his slightly agape mouth, Papyrus’s own tongue flicking across his mouth hungrily and while it was hard to do he managed to propel his hips upward, wanting to hear more of him say his name.

 

“N..Nyeheh..yeah..y-you..nngn like that don’t you? Y-You like feeling..rrr..my cock inside of you, bro?”.

 

“Mwhaaa! Y-Yes! P..Papy..please! Haa..ahhn! M-More! G-Give it to me!”.

 

“Haa Shit! Again. S-Say my name again, Sans”.

 

“P-Papyrus! Papy, p-papy, papy!” Sans cried out as his spine arched, a sudden spot being hit that made his pupils turn into stars at the heavenly burst of pleasure that exploded within him that was almost enough to send him into the galaxy above however reality quickly settled once the sound of fabric being ripped caught his attention, the shorter skeleton letting out a noise in surprise for he found himself toppling backward onto the bed; collapsing on his back with his sibling pinning him to the mattress. Papyrus had literally torn his hoodie in order to break out of his restraints for hearing his beloved brother calling out to him was what drove him beyond his breaking point, panting heavily and gazing down upon him with a mixture of lust and love he didn’t dare stop once he was in control.

 

Now that he had the upper hand he began thrusting roughly, wet noises resounding around the room along with Sans’s higher pitched moans at the change of pace for that spot was continuously hit repeatedly; the mattress squeaking underneath of them.

 

Their bones clanked and rattled faintly from their movements, the older monster’s legs wrapping instinctively over Papyrus’s lilac crests in order for him to go even faster which he did so without a second thought and loving the incoherent words jumbling out of his mouth. “G-God I love you, Sans” he groaned out while his tongue licked across his beloved’s face which was eagerly returned, blue against orange magic mixed together in a sloppy kiss and Sans was able to move his arms to loop around his brothers neck wanting to feel the closeness as much as possible. The smoker wished this moment, this moment that he’d dreamed of for so long, could last for eternity but problem was bodies, even skeletons, had to wear out sometime and after what felt like a good few minutes passing more of their passionate love making he could already sense his brother was close.

 

“Nngh! P..Papy! I..I..mmn! f-feel something strange”.

 

Since this was Sans’s first time he had no idea that what he was experiencing right now, the feeling of something coiling within his non existent gut was his body telling him that he was about to reach his long awaited orgasm and despite the slight worry mixed in his lustful flushed face did the taller monster began to move more frantically; feeling his legs tighten at the sudden shift and wanting to reach the heavens above in time with the other. “Rrr..i.it’s..nngh fuck! Haa..don’t worry, Sans..j-just let it out” Papyrus breathed and nuzzled affectionately in the crook of his brother’s neck with his brows furrowed, jaw clenching as he concentrated the last bit of his strength in ramming himself deeply holding the last bit of his own awaiting climax.

 

Hearing his gasping cries it didn’t long for his older sibling to finally release, feeling his body stiffen underneath him after an elongated groan surfaced from his mouth, trembles running through his bones while he rode the crashing waves of ecstasy. Papyrus himself, after a few more thrusts, managed to finally spill his load after holding it in for so long, a muffled cry of his own escaping as glowing liquid jetted out of his throbbing cock and coating along his siblings spinal cord and ribs. Marking what was his and always would belong to him. 

 

The two siblings now utterly spent did the smoker roll over onto his side in exhaustion, cradling Sans against him as they began to catch their breath while their magical sex organs vanished but traces of what had transpired still dimly lit upon their bodies. For a few minutes neither said anything, just enjoying the silence and the comforting heat of their souls glowing in unison at the love that they shared for one another until finally Sans managed to speak up.

 

“So..that’s what sex feels like?”.

 

N-Nyeheh..yeah pretty much. Did you..not enjoy it?”.

 

He knew that was stupid question to ask but part of him really wanted to be sure that what they did now wouldn’t have an awkward affect on their relationship going forward, that his Sans wouldn’t feel pressured in any way but he would soon eat those words as the other raised himself up a bit in his arms to look at him, his pupils shining excitedly. “What?! Are you kidding?! That was amazing, Paps! Like..really..really amazing” he replied back as his gaze turned shy and he hid his face against the others chest as the reality of the situation sunk in that he’d actually done something like that; with his brother no less. But..he wasn’t upset about it. Heck far from it nor did he regret it. He felt happy, and even more closer to his sibling now then ever before. He never wanted to give that up, even if sure it was taboo and maybe it did worry him what other people would think if they came out together. However he felt positive that as long as Papyrus was with him..things would be alright.

 

At the hug did the lanky monster chuckle, returning it while his chin rested upon Sans’s fontal bone, letting out a content sigh however he couldn’t help it again as another question wracked his skull from earlier, “Sans..? When you said you’d learn to love me..the way I do you..what did you mean by that?”. For a split second when his older brother didn’t answer did the worry start to seep in once more, wondering if he’d made a bad mistake of ever doing this however it melted away like water when he heard his muffled tired voice eventually reply back and the anxiety in his soul release.

 

“W-Well..I just meant that..while I love you as a brother..and part of me does think this is wrong..I..I want to learn how to love you even more then that. I can’t stand the thought of losing you, Papy..I want us to be happy so I hope you’ll understand that..this change will take some time for me to get used to, if you’re alright with that” he replied and felt Papyrus’s arms encase closer around him as a kiss was placed against his skull, the chuckle rumbling from his rib cage.

 

“That’s alright, Sans. I can wait, I’m patient”.

–

End.


End file.
